Dynamo-electric machine



No Model.)

v T. A. EDISON;

DYNAMO ELECTRIC MACHINE. No. 265,785. Patented Oct. 10, 1882.

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THOMAS A. EDISON, OF MENLO PARK, NE\V JERSEY.

DYNAMO-ELECTRIO, MACHINE.

SPECIFICATION forming part of Letters Patent No. 265,785, dated October 10, lEQ.

Application filed August 14, BS2.

To all whom it may concern:

Be it known that I, Tnonas A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Dynamo or Magneto Electric Machines, (Case No. 462;) and I do hereby declare that the following is a full and exact description of the same, reierence being bad to the accompanying drawings, and to the letters of reference marked thereon.

The object of this invention is such an improvement upon thesolid cylindrical armaturecores ofdynamo or magneto electric machines, having a continuously-wound bobbin, composed wholly of wire or of longitudinal bars and suitable cross-connecting disks or plates, that the circulation of Foucault currents in the core will be in a greater measure prevented than heretofore, and the machine will be made 'more efficient by reasonof better obviating the loss of energy caused by this generation of heat; and a further object is to produce simple and et'ficicnt means for this purpose.

This invention relates more especially to an improvement in matter of detail upon the construction described in my application l\o. 5,537, filed March 20, 1880.

The object is accomplished by constructing the armaturecore of an interior core of wood or other suitable insulating material, which is slipped upon the shaft of the armature, and serves to supportthe magueticportion ofthe armature-core,composed ofironringsmadcofthin sheet metal, of from ten to twenty thousandths ofaninch in thickness, (more orless,) divided by rings ot'insulating material, tissue-paper being preferred for the purpose. Clamping-plates of cast-iron are used at the ends of the armature-core, and if the core is long enough to require it one or more intermediate clampingplates may be used, which may be plates extending to the shaft and requiring a division of the interior wooden core; or the intermediate clam pin g-plates may be rings resting like the thin sheet-iron rings upon the wooden core. The clam pin g-plates are preferably drawn and secured together by means of bolts passing through the clamping-plates and through the rings of thin sheet-iron and tissue'paper. Thimblesofproperinsulatingmaterial-such as vulcanized fiber-are placed around the bolts,

(No model.)

where they pass through the clamping-plates, to prevent'the circulation ol'currents between such clamping-plates. 'Theclamping-boltsare also insulated from the thin sheet-iron rings. This is doneby punching the holesin the sheetiron rings slightly larger than the bolts and forcing such bolts through the rings of tissuepaper, which are not punched in advance,causing such tissue-paper to pack in the holes around the bolts, protecting the edges of the sheet-iron rings and effectively insulating such' rings from the bolts. In this way the circulation of currents between the thin sheet-irou rings along the clamping-bolts is prevented. The clamping-plates are keyed or otherwise secured to the armature-shaft, making of the whole a rigid and strong structure.

Instead of using bolts to secure theclampingplates together, such plates may have screwthreaded hubs turning upon screw-threat-led metal thinibles keyed or otherwise secured to thearmattire-shaft; or the clamping-plates may be slipped upon such thimbles and secured by nuts turning upon the lhimbles and impinging against the clainpiugplates, forcing such clamping-plates upon the rings of thin sheetiron and tissue-paper. After the clampingplates are secured the armat ure-corc is mounted in a lathe and turned down smooth, when it will be ready to receive the bobbin, whether composed of wire or of longitudinal bars and suitable cross-connecting disks or plates.

Thet'oregoing will be better understood from the drawings, in which Figure l is a longitudinal section of the armature-core; Fig.2, a separate sectional view of a clam ping-plate around abolt passing therethrough; Fig. 3, a separate sectional view, on an enlarged scale,of portions of several rings of thin sheet-iron and tissuepaper; Fig. 4, a longitudinal section of a modified form of the armaturecore; and Fig. 5, a sectional view of the hub of a clamping-plate, showing a further modification.

A is the armature-shaft, and B the interior core, of wood or other suitableinsulating material, which may be made in onepiece orin two or more sections. The magneticportion ot' the armature-core is composed of rings 0, of sheetiron, of from ten to twenty thousandths o'l" an inch in thickness, (more or less,) separated by suitable insulating material, rings D of tissuepaper being preferably used. These rings of iron and paper are clamped into a solid mass between rigid clamping-plates E F of cast-iron, one or more intermediate clamping-plates, G, Fig. 1, being used if the length of the armature requires such a construction. This intermediate clainpingplate may be a disk extending to the shaft, as shown, and necessitating a division of the wooden core into sections, or it can be made as a ring, resting upon such wooden core. The clamping-plates, are preferably secured together by bolts H, Figs. 1 and 2, which are surrounded by thimbles a of insulating material-such as vulcanized fiberwhere they pass through the plates, in order to prevent the circulation ot'currents between the clamping-plates. The clamping-bolts are also insulated trom the thin sheet-iron rings by making the holesin the sheet-iron rings slightly larger than the bolts. The rings of tissue-paper are not punched in advance, but the bolts are forced through them, spreading the tissuepaperintotheholes over the edges of the sheetiron rings, as shown at I) in Fig. 3. The clamping-platesarc keyed or otherwise secured to the armature-shaft.

Instead of being secured together by bolts, the clamping-plates may have screw-threaded hubs 0 and be turned. upon screw-threaded thimbles d, keyed or otherwise secured to the armature-shaft, Fig. 4, or the clamping-plates may be slipped upon these thimbles and be secured by nuts 0. turned thereon, Fig. 5. After the clamping-plates are secured the armaturecore is mounted in a lathe and turned down smooth, when it is ready to receive the bobbin.

I am aware of the description of Schuckerts dynamo-electricmachineinDinglers Polytechnical Journal, volume 223, pages 587 and 588; but I do not believe that such machine embodies the features of construction described by me and essential in the class of machines to which my dynamo or magneto electric machine belongs.

\Vhat I claim is- 1. In a solid cylindrical armature-core, the combination of an interior core of suitable insulatingmaterial with a magnetic portion composed of rings of thin sheet-iron separated by insulating material, substantially as set forth.

2. An armature-core having its magnetic portion composed of rings of thin sheet-iron separated by insulating material, in combination with clamping-plates, substantially as set forth.

3. In a solid cylindrical armature-core, the combination of the interior core of suitable insulating material with the magnetic portion composed ot'thin sheet-iron rings separated by insulating material, and the clamping-plates, substantially as set forth.

4:. In an armature-core, the combination, with the rings of thin sheet-iron separated by insulation and clamped between plates, of the clamping-bolts insulated from the clampingplates, substantially as set forth.

5. In an armature-core, the combination, with the thin sheet-iron rings separated by insulation, ot' clamping-bolts passing through such thin sheet-iron rings and insulated therefrom, substantially as set forth.

(3. A solid cylindrical armature-core composed of an interior core of insulating material, a magneticportion ot'thin sheet-iron rings separated by insulation. clamping-plates, and clamping-bolts insulated both from the clamping-plates and from the thin sheet-iron rings, the parts being constructed, arranged, and combined substantially as set forth.

This s )ecification si ned and witnessed this 80 7th day of July, 1882.

THOMAS A. EDISON.

Witnesses:

RIOHD. N. DYER, EDWARD H. PYA'IT. 

